This invention relates to technology for moving, storing, cleaning and conditioning fluids. This invention also relates to an oilfield unit having a combination centrifuge, vacuum pump, and conditioning functionalities. The invention may further relate to such a unit that is especially suited for providing such combined functionalities in a single, combination unit that may be provided at the site of a drilling or production unit.
Drilling and production support services for hydrocarbon energies have existed perhaps as long as energy exploration itself. Such support services are required to maintain the fluids that are used in drilling, production and maintenance of the equipment for each step of the process of producing hydrocarbons. Fluids are delivered, utilized, removed from drilling and production sites, and in some scenarios require maintenance such as conditioning, removing impurities, adding other materials for different various functions. Although stand-alone “frac” tanks are capable to be utilized for the purpose of storing the fluids on site, additional maintenance of the fluids must take place off-site.
Fluids used in drilling operations are often combined with other additives, such as mud, to create different fluid profiles depending upon the depth of drilling and other environmental properties found downhole. Drilling rig operators do not always know the profile of the fluid they will need and will order more additive supplies and support services than needed to ensure the continuity of drilling progress. In many cases, a single fluid profile is created off-site and delivered to a storage tank located at the drilling site. In such cases, when drilling rig operators need a different drilling fluid profile they must either use an inadequate drilling fluid or shut down the drilling operation and wait for a new delivery of drilling fluid to be created off-site. The concept of shutting down a drilling rig operation for non-safety issues is anathema to the industry, due to the costs of equipment and labor involved with such a production.
One of the primary functions of fluid maintenance is that of cleaning the fluid of impurities. For exemplary purposes, consider drilling fluid that is used to aid the drilling of boreholes in the earth. On a drilling rig, drilling fluids are drawn from a “mud pit,” through a drill string, carrying with it crushed rock and other debris up the annular space between the drill string and the sides of the bore hole. The drilling fluid is then returns to a mud pit or a tank.
In addition to the crushed rock and debris, drilling fluid can capture other impurities that require removal before reuse. Broadly speaking, the impurities may range in particulate size from large pieces of cement, to smaller metal cuttings to ultrafine particulates. With regards to the medium-to-large particles, fluids are typically stored in mud pits or tanks so that the large particulates settle over a time period of days. This practice requires operators to carry larger inventory of fluids and fluid containers to be available to ensure that the drilling operation continues unabated.
To remove the smaller particulates from drilling fluid, a centrifuge may be utilized. A centrifuge is an item of solids-removal equipment that removes fine and ultrafine solids. Large particulates may damage the centrifuge and its pump, so some preliminary separation of such large particulate impurities is preferred to protect the centrifuge and pump.
A centrifuge may take the shape of a conical drum that rotates at selected rpm. An operator introduces “dirty” or used drilling fluid into one end of the centrifuge, and the solids separate up the bowl to exit at the other end. Centrifuges are useful for processing weighted drilling fluids and can remove fine solids. Centrifuges can also be used for water clarification or for processing oily cuttings.
Centrifuges units are typically located at an energy service facility off-site of the drilling or production site. Given the weight, bulk and expense of the traditional centrifuge unit, the drilling rig operator is reluctant to locate the unit onsite of a busy drilling/production site. This additional step adds further expense and delay, but assures the operator that the recycled drilling fluid will return at desired state of cleanliness. Even if a centrifuge unit were to be placed on site, the matter of moving, storing, and preconditioning fluid before it may enter the centrifuge must be accomplished in a piecemeal, inefficient fashion that results in downtime of a drilling operation.
With regards to managing fluids, an energy production site may present a separate yet related set of challenges for service providers. For example, an oil leak onto a body of water or onto a muddy terrain requires a number of resources. Further, such leaks often occur along pipelines, where access to tools like centrifuge service providers, settling tanks (frac or batteries), and/or skimming devices may be lacking due to the remote location.
In the scenario of an oil leak, effective removal of any leaked fluids from a natural environment is of primary concern. A secondary objective is to manage the removed fluids and any other impact elements—debris, dirt, particulates that have been removed from the site of a leak—in a way that allows efficient and effective separation of each constituent element.
Prior art approaches include using vacuum trucks to remove leaked fluids and affected elements, taking those to another site to separate and manage those fluids and elements off site. Because each task was confined to a separate truck or work site, the workflow for managing and maintaining fluids was limited to the capabilities of the truck, work site, or other piece of equipment. The entire work flow operates without synergy between those tasks, and for creating opportunities to solve challenges on the work site that require short-term solutions rather than those accomplished off-site, with additional equipment that must be scheduled and delivered, all of which bring delay and effectively greater costs.
The present invention solves these problems by providing a combination unit 10 for maintaining fluids that includes functions for vacuuming, storage, screening, conditioning, of the fluids rather than having different trucks, skids, or work sites for each function. Additionally, the present invention provides a combination unit 10 with a plurality of ports for ingress and egress of fluids, allowing a user a plurality of access points and flow patterns to vacuum sources of fluids, clean the fluid of contaminants and particles, introduce desired additives and create conditioned fluids, and hold conditioned fluids until ready for use or discharge into separate storage. The present invention further provides such a combination unit 10 to be capable of delivery to on-site for utility on a drilling rig, a production unit, a pipeline leak or other environments where fluids are desired to be acquired and managed. The present invention even further provides a balanced, multi-functional unit capable of negotiating unimproved, energy lease roads by providing a vacuum storage tank partially incorporated into a mixing tank.